Most of the Yoga I have done/found involves lots of movement into different poses. It seems to me like it would be better to hold certain poses and focus on getting everything lined up right. The DVDs and classes I have used moved into the next pose too quickly to even have time to explain how to be in the pose properly, let alone make sure you are there. Am I overly worried about doing the positions properly?

Kyle, you are very correct in your concern.

For styles that really emphasize alignment, look to Anusara or Iyengar, IMO.